An AIC which is (in effect) found by the Sudocue solver in a "Medusa Bridge" step is

(4)r1c8 = (4-9)r4c8 = (9)r4c4 - (9)r1c4 = (9)r1c6 => r1c6 <> 4

There is also this grouped AIC:

(3=689)r123c4 - (9)r4c4 = (9-3)r6c6 = (3)r56c5 => r3c5 <> 3

After these eliminations no further Medusa steps are needed. After basic follow up, the puzzle is completed with a naked "128" triple in column 1, an X wing for digit 1 in r27c27, then an ER in box 6 for digit 8 which eliminates (8)r4c4.

An AIC which is (in effect) found by the Sudocue solver in a "Medusa Bridge" step is

(4)r1c8 = (4-9)r4c8 = (9)r4c4 - (9)r1c4 = (9)r1c6 => r1c6 <> 4

Is there an equivalent ALS rule and/or Wing structure that reproduces this elimination?

If it helps, this is basically a multi-digit version of 3 Strong Bilocation Links. You have a 4=4 - 9=9 - 9=9 structure where you know one of the endpoints has to be true. Thus, in a way, it belongs to the same family of logic that gives you x-wings, two-tailed kites, and skyscrapers. Of course, an AIC is pattern oriented enough in and of itself.

Well, if you'd asked about the second chain, there is an ALS XZ rule elimination for that elimination. A chain representing this view is

(3=6897)r1234c4 - (7=183)r456c5 => r3c5 <> 3

I'm not sure why I didn't write it this way, other than to say that from other recent work I'm trying to make more use of strong bilocation links in AIC's.

If you're asking if the elimination from the first chain can be obtained from some structure like an ALS XZ or ALS XY wing configuration, or from what some would call a WXYZ wing (or similar configuration with more cells & digits), I can't see anything offhand.